"We believe that the case is closed— supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful. These vitamins should not be used for chronic disease prevention. Enough is enough."

So reads an authoritative editorial today in one of the widest-read U.S. medical journals, Annals of Internal Medicine. The authors are five physicians from Johns Hopkins School of Public Health and Warwick Medical School in the U.K., including one of the journal's senior editors. Each has at least five letters worth of postgraduate degrees after their name.

"Beta-carotene, vitamin E, and possibly high doses of vitamin A supplements are harmful," they specify. "Other antioxidants, folic acid, and B vitamins, and multivitamin and mineral supplements are ineffective for preventing mortality or morbidity due to major chronic diseases."

The editorial is part of the burgeoning consensus that most people do not benefit from vitamin supplements, and that a balanced diet is the best approach, in an ideal world. Dr. Paul Offit wrote about the supplement origin story for us recently—why the default is to think they're good for us, and more means better—in "The Vitamin Myth." One universal, important recommendation for healthy adults remains: Pregnant women should take supplemental folic acid.

The journal article is titled "Enough Is Enough: Stop Wasting Money on Vitamin and Mineral Supplements." If that seems brusque, it's because these experts have watched for years as evidence against the prudence of supplements accumulates, and people buy more and more of them.

"Despite sobering evidence of no benefit or possible harm, use of multivitamin supplements increased among U.S. adults," they write, from 30 to 39 percent between 1988 and 2006. Overall use of dietary supplements also increased, from 42 to 53 percent. "Sales of multivitamins and other supplements have not been affected by major studies with null results, and the U.S. supplement industry continues to grow, reaching $28 billion in annual sales in 2010."